1. Field of the Invention
The present invention relates to a rotating member assembly and a spindle motor including the same.
2. Description of the Related Art
A hard disk drive (HDD), an information storage device, reads data stored on a disk or writes data to the disk using a read/write head.
A hard disk drive requires a disk driving device capable of driving the disk. In the disk driving device, a small-sized spindle motor is used.
This small-sized spindle motor may use a hydrodynamic bearing assembly. A lubricating fluid is interposed between shaft, a rotating member of the hydrodynamic bearing assembly, and a sleeve, a fixed member thereof, such that the shaft is supported by dynamic fluid pressure generated in the lubricating fluid.
In addition, an upper portion of the shaft has a hub rotating together with the shaft and a recoding disk mounted thereon. In the case in which perpendicularity is outside of a normal range by a significant amount in a process of coupling the shaft and the hub, the hub may contact the fixed member, such that rotational performance of the spindle motor may be deteriorated.